A cooperative study of sarcoidosis in Asia and Africa: descriptive epidemiology

Sarcoidosis in tuberculosis-endemic regions: India

Sarcoidosis is a multisystem inflammatory disease of unknown etiology affecting multiple organs. Earlier reports suggested that sarcoidosis was a disease of the developed world. However, recent reports suggest that the disease is found in the developing countries as well. Clinical, radiological, and histopathological similarities with tuberculosis pose a great challenge in countries endemic for tuberculosis. Mantoux test, high resolution computed tomography, and transbronchial lymph node and lung biopsies are diagnostic modalities, which play an important role in the diagnosis of sarcoid. In this review, we look at the epidemiology of sarcoid in tuberculosis-endemic regions, the sarcoidosis-tuberculosis link, clinical profile, diagnostic modalities, dilemma in the diagnosis, and the treatment of this disease.

Analysis of 275 patients with sarcoidosis over a 38 year period; a single-institution experience

BACKGROUND

Sarcoidosis is a systemic granulomatous disease with unknown etiology.

OBJECTIVES

We evaluated seasonal variation, demographic, clinical and diagnostic features of sarcoidosis in recently diagnosed symptomatic patients in the whole cohort (275 patients) and in the subgroups according to the estimated disease course (subacute course group vs. chronic course group). We also developed a prediction model to predict the course of sarcoidosis using simple clinical and demographic variables.

MATERIAL AND METHODS

Two hundred and seventy-five patients with sarcoidosis. MEASUREMENTS AND STATISTICS: Roger's test, chi-square, t-test and multiple logistic regression were used.

RESULTS

The distribution of cumulative monthly diagnosis was the lowest in November (fall) (p<0.01). Seasonal pattern was influenced by age and gender. Constitutional symptoms, stages 2 and 3 diseases and the absence of erythema nodosum were highly significant parameters for chronic course. Using these variables, the developed model had a specificity of 93.1% and its positive predictive value was 89.5%. Progression of the disease was documented 6.4% in subacute group vs. 32.1% in chronic group (p=0.00001). Preventive effect of smoking was more pronounced in females than in males in our cohort.

CONCLUSIONS

Further well-designed and large prospective studies are required to better understand the importance of these findings, and to validate the prediction model presented here.

Seasonal variation of the onset of presentations in stage 1 sarcoidosis

Sarcoidosis is a chronic disease with an unknown aetiology. Our aim was to evaluate the pattern of seasonality of stage 1 sarcoidosis subjects who had symptoms by all cases, by age and by both genders. In this study, we used Roger's test for cyclic variation to prove that this seasonal variation was more than chance. Four hundred ninety-two consecutive patients with sarcoidosis who presented different clinical symptoms were included in this retrospective cohort study. According to the chest X-ray examinations, 185 patients had stage 1, while 307 patients in control group had stage 0, 2, 3 and 4 sarcoidosis. The demographic features, presenting clinical features, course of the disease, initial diagnostic methods and both the month and the age at the initial diagnosis for each patient were analysed on chart reviews. Roger's test for cyclic variation was used to determine the significance of any seasonal variation of incidence. Otherwise, t-test was used. The distribution of cumulative monthly presentations for patients with stage 1 peaked in April (108% above the average) and was lowest in October, November and December (48% below the average) (p < 0.001). Seasonality of the control group peaked in May (84% above the average) and was lowest in August (69% below the average) (p < 0.001). The seasonal pattern of subjects within both groups was influenced by some age groups and by both genders (p < 0.05). Some differences in the amplitude of the seasonal variation by age and by both genders increase the possibility of interactions among age, gender and the disease. Further well-designed and prospective studies are required to better understand the importance of our findings and the pathogenesis of the disease.

Analysis of 87 patients with Lofgren's syndrome and the pattern of seasonality of subacute sarcoidosis

BACKGROUND AND OBJECTIVE

Sarcoidosis is a multisystem disease of unknown aetiology. The seasonality of sarcoidosis in symptomatic, recently diagnosed patients with Löfgren's syndrome was evaluated to help better understand the possible causative factor(s) in the pathogenesis of sarcoidosis.

METHODS

Four hundred and ninety-two consecutive patients with sarcoidosis were investigated. The demographic and clinical features, course of the disease, initial diagnostic methods and both the month and age at initial diagnosis for each patient were analysed. Roger's test for cyclic variation was used to determine the significance of any seasonal variation of incidence.

RESULTS

Löfgren's syndrome was diagnosed in 87 patients (18%). The diagnosis of sarcoidosis was delayed in 45% of subjects (mean: 11.2 weeks). The distribution of cumulative monthly presentations peaked in May (spring) and was the lowest in January (winter) and November (autumn) (P < 0.001). The seasonal pattern was also influenced by age and gender (P < 0.05). At the onset, arthralgia was present in 46%, cough or dyspnoea in 37%, constitutional symptoms in 32% and skin lesions in 30% of the patients.

CONCLUSIONS

In this study, there were differences in the amplitude of the seasonal variation by age and by gender. Well-designed prospective studies are required to better understand the importance of the findings we respect to the pathogenesis of the disease.

Sarcoid arthritis: clinical characteristics, diagnostic aspects, and risk factors

OBJECTIVES

(a) To describe the clinical characteristics of acute sarcoid arthritis and the diagnostic value of its presenting clinical features; (b) to evaluate whether disease onset is seasonal; and (c) to evaluate whether smoking behaviour or the presence of HLA class II alleles is a risk factor for the disease.

METHODS

579 consecutive patients with recent onset arthritis who had been newly referred to a rheumatology outpatient clinic were included in a prospective cohort study. The presenting clinical features, the smoking behaviour, and the results of HLA-DQ and HLA-DR DNA typing of 55 patients with sarcoid arthritis, 524 patients with other arthritides of recent onset, and samples of the normal population were compared.

RESULTS

In all cases the disease showed a self limiting arthritis and overall good prognosis. The diagnostic ability of a combination of four clinical features--symmetrical ankle arthritis, symptoms of less than two months, age below 40 years, and erythema nodosum--was exceptionally high. When test positivity is defined as the presence of at least three of four criteria the set rendered a sensitivity of 93%, a specificity of 99%, a positive predictive value of 75%, and a negative predictive value of 99.7%. The disease clustered in the months March-July. The disease was negatively associated with smoking (odds ratio (OR) 0.09; 95% confidence interval (95% CI) 0.02 to 0.37) and positively associated with the presence of the DQ2 (DQB1*0201)-DR3 (DRB1*0301) haplotype (OR 12.33; 95% CI 5.97 to 25.48).

CONCLUSION

The disease entity acute sarcoid arthritis has highly diagnostic clinical features. The seasonal clustering, the protective effect of smoking, and the association with specific HLA class II antigens support the hypothesis that it results from exposure of susceptible hosts to environmental agents through the lungs.

Sarcoidosis in developing countries

Sarcoidosis is seen in different parts of India and other developing countries with almost similar frequency as in the West. It was largely due to lack of awareness and non-availability of investigations for diagnosis that the disease was reported to be rare in the past. A combination of clinical, radiologic, and histologic criteria are used to diagnose sarcoidosis. A confident exclusion of other causes of granuloma formation, especially tuberculosis, is required. Absence of mycobacteria and of caseation in the histologic specimens and presence of skin anergy to tuberculin help make a diagnosis. Transbronchial lung biopsy obtained with the help of fiberoptic bronchoscopy is positive in about 80% of patients. Corticosteroids are used to treat patients with symptoms and those showing active organ involvement. Aggressive treatment is required for patients with acute and severe pulmonary, cardiac, ocular, or neurologic involvements.

Could Borrelia burgdorferi be a causal agent of sarcoidosis?

Sarcoidosis is a multisystem granulomatous disorder of unknown etiology, most commonly affecting young adults presenting most frequently with bilateral hilar lymphadenopathy, pulmonary infiltrations, skin or eye lesions (1). Borrelia burgdorferi, the causal agent of Lyme disease, could also be responsible for sarcoidosis. Domestic animals may play a major role in transmitting the disease to humans. The modes of transmission to such animals and possible contact transmission to humans are still obscure and should be more fully investigated. Small rodents have been found to play a role as reservoirs for Borrelia burgdorferi. They are suspected to constitute an important source of contamination for domestic animals. The author explains in this paper how geographic distribution and familial occurrence of sarcoidosis as well as racial differences in the incidence of this disease, could be related to such findings.

Sarcoidosis in Caucasians, Blacks and Asians in London

The incidence and clinical features of sarcoidosis were studied in a retrospective survey of 156 patients attending two South London hospitals between 1969 and 1982. Sixty-eight patients were Caucasian, 59 were Black West Indian or African immigrants and 29 were immigrants racially derived from Indo-Pakistan (Asians). The annual incidence of sarcoidosis in the local community in 1977-78 was 19.8 per 10(5) for Blacks and 16.8 per 10(5) for Asians compared with 1.5 per 10(5) for Caucasians. Erythema nodosum was a more common presenting feature in Caucasians than in Blacks (P less than 0.001) or Asians (P less than 0.05). Blacks developed sarcoidosis at a later age than Caucasians (P less than 0.05) and were less likely to present as a chance finding on a chest radiograph (P less than 0.05). They had more widespread extrathoracic disease than Caucasians (P less than 0.001) and were more commonly treated with corticosteroids (P less than 0.001). In the Asians there was a male predominance compared with Caucasians (P less than 0.01). Asians also had more extrathoracic sarcoidosis than Caucasians (P less than 0.001) and more of them were treated with corticosteroids (P less than 0.05). A stage 2 chest radiograph at presentation (P less than 0.05) and skin sarcoidosis (P less than 0.05) were less common in Asians than in Blacks, but otherwise there were no significant differences between the two groups. In this study the incidence of sarcoidosis in Asians approached that in Blacks, while the clinical features were intermediate in severity between Blacks and Caucasians. In both Blacks and Asians the disease was more common, more severe and more extensive than in Caucasians.